Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM accessfunctions

2014-10-23 Thread Guenter Roeck

On 10/23/2014 11:55 AM, Florian Fainelli wrote:

On 10/23/2014 11:41 AM, Chris Healy wrote:

Hi Guenter,

I do not believe it is possible to know if an EEPROM is attached or not.


If we cannot do this, how about a DT/platform data set of properties
that describes the EEPROM when present?


Yes, I think that is a good idea.

Thanks,
Guenter



Chris

From: Guenter Roeck [li...@roeck-us.net]
Sent: Thursday, October 23, 2014 9:40 AM
To: Andrew Lunn
Cc: net...@vger.kernel.org; David S. Miller; Florian Fainelli; 
linux-kernel@vger.kernel.org; Chris Healy
Subject: Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM 
accessfunctions

On Thu, Oct 23, 2014 at 03:54:12PM +0200, Andrew Lunn wrote:

On Wed, Oct 22, 2014 at 09:03:18PM -0700, Guenter Roeck wrote:

MV88E6352 supports read and write access to its configuration eeprom.


Hi Guenter

I don't have the datasheet for the MV88E6352. Is the EEPROM built in,
or external on an i2c bus?


External.


+static int mv88e6352_get_eeprom_len(struct dsa_switch *ds)
+{
+   return 0x200;
+}


How do you handle the case of it being external and not populated.
Would it not be better to try to detect it here, and return 0 if it
does not exist?


Makes sense, if it is detectable that it the EEPROM not there. Browsing
through the datasheet, I don't see how I could detect it; there does not
seem to be a status bit indicating if the EEPROM is there or not. There
are sw_mode pins which determine if the eeprom should be loaded after
reset or not, but I don't see anything in the register set which would
tell me.

Chris, do you know if there is a means to detect if the EEPROM is present
on the MV88E6352 ?

Thanks,
Guenter




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Systems and Software Enterprises, LLC. This information is intended solely for the 
use of the individual or entity to which it is addressed. Access or transmittal of 
the information contained in this e-mail, in full or in part, to any other 
organization or persons is not authorized.






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Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM accessfunctions

2014-10-23 Thread Florian Fainelli
On 10/23/2014 11:41 AM, Chris Healy wrote:
> Hi Guenter,
> 
> I do not believe it is possible to know if an EEPROM is attached or not.

If we cannot do this, how about a DT/platform data set of properties
that describes the EEPROM when present?

> 
> Chris
> 
> From: Guenter Roeck [li...@roeck-us.net]
> Sent: Thursday, October 23, 2014 9:40 AM
> To: Andrew Lunn
> Cc: net...@vger.kernel.org; David S. Miller; Florian Fainelli; 
> linux-kernel@vger.kernel.org; Chris Healy
> Subject: Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM 
> accessfunctions
> 
> On Thu, Oct 23, 2014 at 03:54:12PM +0200, Andrew Lunn wrote:
>> On Wed, Oct 22, 2014 at 09:03:18PM -0700, Guenter Roeck wrote:
>>> MV88E6352 supports read and write access to its configuration eeprom.
>>
>> Hi Guenter
>>
>> I don't have the datasheet for the MV88E6352. Is the EEPROM built in,
>> or external on an i2c bus?
>>
> External.
> 
>>> +static int mv88e6352_get_eeprom_len(struct dsa_switch *ds)
>>> +{
>>> +   return 0x200;
>>> +}
>>
>> How do you handle the case of it being external and not populated.
>> Would it not be better to try to detect it here, and return 0 if it
>> does not exist?
>>
> Makes sense, if it is detectable that it the EEPROM not there. Browsing
> through the datasheet, I don't see how I could detect it; there does not
> seem to be a status bit indicating if the EEPROM is there or not. There
> are sw_mode pins which determine if the eeprom should be loaded after
> reset or not, but I don't see anything in the register set which would
> tell me.
> 
> Chris, do you know if there is a means to detect if the EEPROM is present
> on the MV88E6352 ?
> 
> Thanks,
> Guenter
> 
> 
> 
> 
> This email and any files transmitted with it are confidential & proprietary 
> to Systems and Software Enterprises, LLC. This information is intended solely 
> for the use of the individual or entity to which it is addressed. Access or 
> transmittal of the information contained in this e-mail, in full or in part, 
> to any other organization or persons is not authorized.
> 

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RE: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM accessfunctions

2014-10-23 Thread Chris Healy
Hi Guenter,

I do not believe it is possible to know if an EEPROM is attached or not.

Chris

From: Guenter Roeck [li...@roeck-us.net]
Sent: Thursday, October 23, 2014 9:40 AM
To: Andrew Lunn
Cc: net...@vger.kernel.org; David S. Miller; Florian Fainelli; 
linux-kernel@vger.kernel.org; Chris Healy
Subject: Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM 
accessfunctions

On Thu, Oct 23, 2014 at 03:54:12PM +0200, Andrew Lunn wrote:
> On Wed, Oct 22, 2014 at 09:03:18PM -0700, Guenter Roeck wrote:
> > MV88E6352 supports read and write access to its configuration eeprom.
>
> Hi Guenter
>
> I don't have the datasheet for the MV88E6352. Is the EEPROM built in,
> or external on an i2c bus?
>
External.

> > +static int mv88e6352_get_eeprom_len(struct dsa_switch *ds)
> > +{
> > +   return 0x200;
> > +}
>
> How do you handle the case of it being external and not populated.
> Would it not be better to try to detect it here, and return 0 if it
> does not exist?
>
Makes sense, if it is detectable that it the EEPROM not there. Browsing
through the datasheet, I don't see how I could detect it; there does not
seem to be a status bit indicating if the EEPROM is there or not. There
are sw_mode pins which determine if the eeprom should be loaded after
reset or not, but I don't see anything in the register set which would
tell me.

Chris, do you know if there is a means to detect if the EEPROM is present
on the MV88E6352 ?

Thanks,
Guenter




This email and any files transmitted with it are confidential & proprietary to 
Systems and Software Enterprises, LLC. This information is intended solely for 
the use of the individual or entity to which it is addressed. Access or 
transmittal of the information contained in this e-mail, in full or in part, to 
any other organization or persons is not authorized.
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RE: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM accessfunctions

2014-10-23 Thread Chris Healy
Hi Guenter,

I do not believe it is possible to know if an EEPROM is attached or not.

Chris

From: Guenter Roeck [li...@roeck-us.net]
Sent: Thursday, October 23, 2014 9:40 AM
To: Andrew Lunn
Cc: net...@vger.kernel.org; David S. Miller; Florian Fainelli; 
linux-kernel@vger.kernel.org; Chris Healy
Subject: Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM 
accessfunctions

On Thu, Oct 23, 2014 at 03:54:12PM +0200, Andrew Lunn wrote:
 On Wed, Oct 22, 2014 at 09:03:18PM -0700, Guenter Roeck wrote:
  MV88E6352 supports read and write access to its configuration eeprom.

 Hi Guenter

 I don't have the datasheet for the MV88E6352. Is the EEPROM built in,
 or external on an i2c bus?

External.

  +static int mv88e6352_get_eeprom_len(struct dsa_switch *ds)
  +{
  +   return 0x200;
  +}

 How do you handle the case of it being external and not populated.
 Would it not be better to try to detect it here, and return 0 if it
 does not exist?

Makes sense, if it is detectable that it the EEPROM not there. Browsing
through the datasheet, I don't see how I could detect it; there does not
seem to be a status bit indicating if the EEPROM is there or not. There
are sw_mode pins which determine if the eeprom should be loaded after
reset or not, but I don't see anything in the register set which would
tell me.

Chris, do you know if there is a means to detect if the EEPROM is present
on the MV88E6352 ?

Thanks,
Guenter




This email and any files transmitted with it are confidential  proprietary to 
Systems and Software Enterprises, LLC. This information is intended solely for 
the use of the individual or entity to which it is addressed. Access or 
transmittal of the information contained in this e-mail, in full or in part, to 
any other organization or persons is not authorized.
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM accessfunctions

2014-10-23 Thread Florian Fainelli
On 10/23/2014 11:41 AM, Chris Healy wrote:
 Hi Guenter,
 
 I do not believe it is possible to know if an EEPROM is attached or not.

If we cannot do this, how about a DT/platform data set of properties
that describes the EEPROM when present?

 
 Chris
 
 From: Guenter Roeck [li...@roeck-us.net]
 Sent: Thursday, October 23, 2014 9:40 AM
 To: Andrew Lunn
 Cc: net...@vger.kernel.org; David S. Miller; Florian Fainelli; 
 linux-kernel@vger.kernel.org; Chris Healy
 Subject: Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM 
 accessfunctions
 
 On Thu, Oct 23, 2014 at 03:54:12PM +0200, Andrew Lunn wrote:
 On Wed, Oct 22, 2014 at 09:03:18PM -0700, Guenter Roeck wrote:
 MV88E6352 supports read and write access to its configuration eeprom.

 Hi Guenter

 I don't have the datasheet for the MV88E6352. Is the EEPROM built in,
 or external on an i2c bus?

 External.
 
 +static int mv88e6352_get_eeprom_len(struct dsa_switch *ds)
 +{
 +   return 0x200;
 +}

 How do you handle the case of it being external and not populated.
 Would it not be better to try to detect it here, and return 0 if it
 does not exist?

 Makes sense, if it is detectable that it the EEPROM not there. Browsing
 through the datasheet, I don't see how I could detect it; there does not
 seem to be a status bit indicating if the EEPROM is there or not. There
 are sw_mode pins which determine if the eeprom should be loaded after
 reset or not, but I don't see anything in the register set which would
 tell me.
 
 Chris, do you know if there is a means to detect if the EEPROM is present
 on the MV88E6352 ?
 
 Thanks,
 Guenter
 
 
 
 
 This email and any files transmitted with it are confidential  proprietary 
 to Systems and Software Enterprises, LLC. This information is intended solely 
 for the use of the individual or entity to which it is addressed. Access or 
 transmittal of the information contained in this e-mail, in full or in part, 
 to any other organization or persons is not authorized.
 

--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
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Please read the FAQ at  http://www.tux.org/lkml/


Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM accessfunctions

2014-10-23 Thread Guenter Roeck

On 10/23/2014 11:55 AM, Florian Fainelli wrote:

On 10/23/2014 11:41 AM, Chris Healy wrote:

Hi Guenter,

I do not believe it is possible to know if an EEPROM is attached or not.


If we cannot do this, how about a DT/platform data set of properties
that describes the EEPROM when present?


Yes, I think that is a good idea.

Thanks,
Guenter



Chris

From: Guenter Roeck [li...@roeck-us.net]
Sent: Thursday, October 23, 2014 9:40 AM
To: Andrew Lunn
Cc: net...@vger.kernel.org; David S. Miller; Florian Fainelli; 
linux-kernel@vger.kernel.org; Chris Healy
Subject: Re: [PATCH 10/14] net: dsa/mv88e6352: Implement EEPROM 
accessfunctions

On Thu, Oct 23, 2014 at 03:54:12PM +0200, Andrew Lunn wrote:

On Wed, Oct 22, 2014 at 09:03:18PM -0700, Guenter Roeck wrote:

MV88E6352 supports read and write access to its configuration eeprom.


Hi Guenter

I don't have the datasheet for the MV88E6352. Is the EEPROM built in,
or external on an i2c bus?


External.


+static int mv88e6352_get_eeprom_len(struct dsa_switch *ds)
+{
+   return 0x200;
+}


How do you handle the case of it being external and not populated.
Would it not be better to try to detect it here, and return 0 if it
does not exist?


Makes sense, if it is detectable that it the EEPROM not there. Browsing
through the datasheet, I don't see how I could detect it; there does not
seem to be a status bit indicating if the EEPROM is there or not. There
are sw_mode pins which determine if the eeprom should be loaded after
reset or not, but I don't see anything in the register set which would
tell me.

Chris, do you know if there is a means to detect if the EEPROM is present
on the MV88E6352 ?

Thanks,
Guenter




This email and any files transmitted with it are confidential  proprietary to 
Systems and Software Enterprises, LLC. This information is intended solely for the 
use of the individual or entity to which it is addressed. Access or transmittal of 
the information contained in this e-mail, in full or in part, to any other 
organization or persons is not authorized.






--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
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